Hybrid catheter for vascular intervention

ABSTRACT

A catheter for debulking of an undesired deposit from an inner surface of at least one of a blood vessel wall and a stent located in a blood vessel, the catheter having a tip section comprising: circumferentially-directed laser optics; and a circular-action cutter, wherein said circumferentially-directed laser optics is configured to transmit laser radiation for modifying an area of the undesired deposit thereby preparing said area for penetration of said cutter, wherein said cutter is configured to cut through said modified area and thereby debulk at least a part of the undesired deposit. In addition, a catheter for pacemaker and ICD (Implantable Cardioverter Defibrillator) lead extraction is disclosed.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.15/649,234, filed Jul. 13, 2017 (published as 20170304004), which is acontinuation of U.S. patent application Ser. No. 14/001,633, filed Aug.26, 2013 (now U.S. Pat. No. 9,730,756), which is the U.S. National Stageof International Application No. PCT/IL2012/000088, filed Feb. 23, 2012,which claims the benefit of U.S. Provisional Application Nos.61/521,523, filed Aug. 9, 2011, and 61/446,145, filed Feb. 24, 2011, thecontents of each of which are incorporated herein by reference in theirentireties.

FIELD OF THE INVENTION

The invention relates to a hybrid catheter for vascular or otherinterventions.

BACKGROUND OF THE INVENTION

Peripheral and arterial vascular diseases are a common problem which maydirectly lead to morbidity and death. In the U.S. alone it is estimatedthat over 4 million people suffer from peripheral artery disease which,in severe cases, is treated with surgery or even amputation.

Flat lesions represent a significant challenge in gastroenterology.Removing of sessile and flat polyps, which may be associated with highrisk for malignancy, requires, in most cases, usage of differenttechniques than those used for removing common polyps. These techniquesmay lead to the referral of patients to surgery instead of removal bythe gastroenterologist. Other challenging lesions are nonpolypoidcolorectal neoplasms (NP-CRNs). Barrett's esophagus is another commonchronic condition. The prevalence in the U.S. population is estimated tobe in the range of 1-2% of the adult population. Barrett's esophaguscondition may lead to violent esophageal cancer, which is said to resultin over 12,000 deaths per year in the U.S. alone and around 100,000 inChina.

Laser and Mechanical Based Solutions for Angioplasty, Atherectomy andThrombectomy:

The current state of the art in laser ablation technology for vascularintervention is based on use of an Excimer lasers with dedicatedcatheters such as Spectranetics' CVX-300® laser and TURBO-Booster®catheter. These technologies are described, for example, in U.S. Pat.Nos. 6,673,064, 7,811,281 and 7,572,254. Due to technical and safetyconsiderations, the excimer laser used, generally, is often a XenonChloride laser operative at 308 nm with pulse widths in the range of 100nanoseconds. These technologies are not ideal and have some limitations.For example, when dealing with heavy calcified plaques, there is a riskof perforation and damage from debris/plaque fragments. Therefore, theprocedure requires a complex, large and costly system and the length ofthe procedure is quite significant in a manner that seems to limit itswide clinical utility. In addition, the technique had difficulties intreatment of large vessels such as SFA (Superficial Femoral Artery)which is very important in management of peripheral artery disease (PAD)wherein vessels larger than 4-5 mm in diameter and long lesions have tobe treated.

One of the reasons for the length of the process is that even one of themost advanced solutions, combining the TURBO-Booster® and the TURBOLaser Elite catheters, may require a number of steps starting withatherectomy to create an initial pilot channel through the whole lesion,for example using the laser catheter alone, and only at later stages thelaser catheter is loaded into the introducer sheath. The use of thecatheter is based on several passages, each after rotation of thecatheter. See Schwarzwalder U, Zeller T, Tech Vasc Interv Radiol. 2010March; 13(1):43-53.

Additional limitations of this solution include ineffective removal ofarterial debris and high risk of artery walls injury, as mentioned, forexample, in U.S. Pat. No. 6,962,585:

-   -   “An Excimer Laser Coronary Angioplasty system and procedure        offered by Spectranetics of Colorado Springs, Colo., involves        the insertion into an artery of a laser catheter containing a        bundle of optical fibers and a stent with a guide wire. The        laser catheter is advanced in the artery until the guide wire        crosses a blockage, at which time bursts of ultraviolet (cool)        laser light is transmitted through the fiber optic fibers to        open a hole in the blockage. Thereafter, an x-ray contrast dye        is injected into the blood stream to determine the extent to        which the artery has been opened. This procedure does not remove        substantial amounts of blockage because ultra violet radiation        is too cool to melt the blockage. Rather, a hole is blasted        through the blockage to accommodate the admission of a stent.        While the catherization system includes a filter, the filter is        not sufficient to catch all debris which may flow downstream.    -   Such prior systems have failed because they have not effectively        removed arterial blockage from the artery walls, and have not        effectively removed arterial debris from the artery once the        arterial blockage has been dislodged. In addition, such prior        systems have not adequately protected the artery walls from        physical or thermal injury. Further, many of the prior art        devices embody numerous parts which tend to fail or shatter in a        high temperature/high vacuum environment.” (id, p. 1, ln. 19)

An alternative approach using IR laser for thermal heating of a tip usedto cut the plaques to be removed with suction is disclosed in U.S. Pat.No. 6,962,585. This approach may suffer from the limitations and riskinvolved with plaque removal based on non-selective heating. Theapproach proposed in this case is to use arterial guards in the outerpart of the catheter that may limit the passage of the catheter andavoid getting closer to the walls. Other attempts to use thermal effectsinclude a hybrid thermal probe, wherein most of the laser energy (Argonor Nd:YAG) is used to heat the hot tip in the catheter, and part of itescapes as laser light. Clinical results were not satisfactory to enableroutine clinical use.

Additional prior approaches include use of a laser to core the plaqueand use of mechanical means to “ingest” and remove the plaque. See, forexample, U.S. Pat. No. 4,979,939. In Canadian Patent No. 1,326,800 afiber is introduced to create an opening through which the distal rotaryis introduced and the second fiber is used to vaporize the materialcollected by the blade. U.S. Patent Application Publication No.2010/0125253 discloses a dual tip catheter for treating chronic totalocclusions through which a fiber may be introduced.

In view of the complexity and limitations of the laser basedtechnologies, the systems based on excimer laser have had limited spreadin clinical use, and alternative mechanical methods for atherectomy havebeen developed, for example, wherein the plaques are “shaved” (the EV3product), “drilled” (the Pathway product) or “sanded” with a rotatingdiamond coated brush (the CSI product). Each of these techniques mayoften suffer from inherent limitations such as procedure length, injuryto the blood vessels, difficulty in dealing with calcified plaques incertain cases and, on the contrary, dealing with soft plaque (seeSchwarzwalder U, Zeller T, Tech Vasc Intery Radiol. 2010 March;13(1):43-53) or discarding of plaque material into the blood stream.

It should be noted that it is assumed by experts in the area that injuryof healthy tissue and the characteristics of the tissue after plaque isremoved may affect the healing (and initial hyperplasia) and the rate ofrestenosis which seems to be a limitation of some of the above-mentionedtechniques. Furthermore, in view of the limited capabilities to removeplaque with many prior techniques, their current utility is limitedmainly for use in conjunction with low pressure balloon angioplasty usedafter plaque is partially removed. The balloon then opens the vesselwith the remaining plaque material.

The need to deal with complete or partial blockage in vessels appliesalso to artificial grafts, such as those implanted in the legs forbypass, for hemodialyisis access and more.

In-stent—restenosis. It is known in the art that in a significantpercentage of the patients that underwent stent implantation, restenosisoccurs within a few years after implantation. This is a major issue withbare-metal stents (BMS) and even introduction of drug eluting stents(DES) that show a robust decrease of restenosis still does notcompletely solve the problem.

Acute blockage of vessels. There is also a need for tools that quicklyopen blood vessels in patients that suffer from ischemic stroke (causedby blockage of a blood vessel) or in heart attacks with the minimal riskof perforation.

Removal of pacemaker and defibrillator leads. Presently there is agrowing need to remove pacemaker and defibrillators leads in a subset ofpatients due to several reasons such lead fracture, abrasion of theinsulation causing shorting and infections. Approximately 5 millionleads are implanted worldwide and it is estimated that 4-7% will have tobe removed at certain time point. It is estimated that over 100,000leads were extracted in the US and Europe in 2010.

There are several approaches to remove transvenously introduced ICDleads. If leads have been in place for only a short period, they canfrequently be removed by simple traction. After the leads are in placefor long time scar tissue may withholds the leads during traction, theforce applied to the leads is limited by the tensile strength of theinsulation and conductor coils, therefore locking stylets and sheathsare used to enable a more forceful tension, but successful lead removalcan still be very problematic when the leads is attached to sensitivetissue such myocardial wall. In severe cases lead extraction may requireopen surgery. The Spectranetics Excimer Laser and Cook Medical'sEvolution products are currently used for lead removal usingtranscatheter techniques. The “debulking” of the lead using an excimerlaser has yielded good clinical results but requires a large andexpensive laser that does not allow wide use in any cardiology unit anda relative long learning curve is required.

There is a need for an effective and safe solution for removal ofpacemakers and defibrillator leads in patients.

Management of Barrette's Esophagus. Barrett's Esophagus (BE) is a commondisorder that is a major risk factor for esophagus cancer. Theprevalence of the disorder is estimated to be in the range of 1-2%. SeeRonkainen J, Aro P, Storskrubb T, et al. (December 2005) “Prevalence ofBarrett's esophagus in the general population: an endoscopic study”,Gastroenterology 129 (6): 1825-31. The range of severity can vary fromearly stage to different grades of dysplasia to cancer. Prior attemptsto manage this condition with Argon coagulation yielded controversialresults. Alternative methods are based on RF ablation (RFA) (Halo®System), photodynamic therapy (PDT), cryo, thermal therapy or surgery asendoscopic mucosal resection (EMR). No method resulted in wide clinicalacceptance that can enable routine use in a broad population instead of“waiting and watching” in early stages in the disease and specifictherapies including esophagus resection in more sever conditions.

Furthermore, as no single technique has been established as thepreferred method, a combination of techniques is used in certain cases.For example, there may be a consensus that RFA is useful for patientswith BE and high-grade dysplasia (HGD), BE and intramucosal carcinoma asan adjunct to endoscopic mucosal resection (EMR). The use of RFA for BEwith low-grade dysplasia (LGD) or intestinal metaplasia is not clearlyestablished, see David E. Fleischer Virender K. Sharma, Interventionaland Therapeutic Gastrointestinal Endoscopy. Front Gastrointest Res.Basel, Karger, 2010, vol 27, pp 140-146. On the other hand, EMRsometimes does not allow removing all of the Barrett's lining but can besuccessful in removing a small cancer or a localized area of high-gradedysplasia. Because it does not remove all of the Barrett's lining, theBarrett's lining left behind can develop other areas of high-gradedysplasia or cancer. Therefore, EMR is sometimes combined withphotodynamic therapy in an attempt to remove remaining Barrett's tissueor with RF ablation. Conversely, several photodynamic therapy studieshave also reported that a few patients have a situation in which theBarrett's lining does not completely go away but is still there,underneath the new normal-appearing squamous lining (and detected whenbiopsy is performed that shows that small areas of Barrett's lining arestill there underneath the new squamous lining.) In such a case, anothercourse of treatment with another technique might be beneficial.

Complications of the current available techniques include perforations(making a hole in the esophagus), bleeding, strictures, lightsensitivity in PDT and even death.

Removal of challenging lesions in intestine and stomach. Some of thepolyps and adenomas (benign tumors) detected with an increasing percentin colonoscopy, with different imaging techniques, do not have aconventional “pedunculated” shape. Polyps that are not attached to thesurface by a narrow elongated stalk are called sessile. Other polyps arenot significantly elevated from the adjacent mucosa are called flat.Accordingly, the removal of large sessile and flat colorectal is moredifficult than removal of pedunculated polyps and in many cases requireusing special endoscopy techniques to avoid perforation.

These lesions may be associated with high clinical risk. The incidenceof cancer with submucosal invasion appears to be higher in flat-typelateral spreading tumors.

Endoscopic Mucosal Resection (EMR) is becoming the standard techniquefor resection of large sessile and flat colorectal lesions. For the morechallenging lesions, Endoscopic Submucosal Dissection (ESD) can be used.ESD can be performed using a viscous injection solution for sustainedsubmucosal lifting, a diathermy knife, and a plastic hood to helpretract the polyp as it is dissected away from the muscularis propria.

Although these techniques are feasible anywhere in the colon, currentlythese techniques are technically challenging and time consuming and ESDcarries a relatively high rate of major complication. Laser ablation isusually not perceived as an adequate solution for this application, asthere is a need to assure adequate (i.e. complete) removal ofpathological tissue and preferably to collect resected samples forhistological analysis

There is thus an unmet need in the art for devices, systems and methodsthat would allow efficient and effective vascular interventions as wellas removal of challenging lesions in the gastroenterology (GI) track(mainly in colon and stomach) and Barrett's esophagus management.

Removal of challenging lesions in gynecology and urology. There is aneed for effective and safe tools for removal of pathological tissue ingynecology (cervical uterus) and urology (urinary bladder, prostate),wherein the depth of resection can be controlled while risk ofperforation and bleeding is minimized.

SUMMARY OF THE INVENTION

There is provided, in accordance with some embodiments, a catheter fordebulking of an undesired deposit from an inner surface of at least oneof a blood vessel wall and a stent located in a blood vessel, thecatheter having a tip section comprising: circumferentially-directedlaser optics; and a circular-action cutter, wherein saidcircumferentially-directed laser optics is configured to transmit laserradiation for modifying an area of the undesired deposit therebypreparing said area for penetration of said cutter, wherein said cutteris configured to cut through said modified area and thereby debulk atleast a part of the undesired deposit.

There is further provided, in accordance with some embodiments, a methodfor debulking of undesired deposit from an inner surface of at least oneof a blood vessel wall and a stent located in a blood vessel, the methodcomprising, using a catheter: irradiating an area of the undesireddeposit using a circumferentially-directed laser optics, therebymodifying said area; and cutting through said modified area using acircular-action cutter, thereby debulking at least a part of saidundesired deposit.

There is further provided, in accordance with some embodiments, acatheter for debulking of an undesired deposit from an inner surface ofat least one of a blood vessel wall and a stent located in a bloodvessel, the catheter having a tip section comprising: a first wallhaving a circular cross section and having a sharp distal edge; and aplurality of optical fibers located along the surface of said firstwall, wherein said plurality of optical fibers are configured totransmit laser radiation configured to modify the undesired deposit andthereby preparing the undesired deposit for penetration of said sharpdistal edge of said first wall, wherein said first wall is configured tocut through said modified undesired deposit and thereby debulk at leasta part of the undesired deposit.

There is further provided, in accordance with some embodiments, a methodfor debulking of undesired deposit from an inner surface of at least oneof a blood vessel wall and a stent located in a blood vessel, the methodcomprising, using a catheter: using a catheter having a plurality ofoptical fibers, transmitting laser radiation towards an undesireddeposit thereby modifying the undesired deposit and preparing theundesired deposit for penetration of a sharp distal edge of a catheter'swall; and advancing the catheter and cutting through the modifiedundesired deposit thereby debulking at least a part of said undesireddeposit.

There is further provided, in accordance with some embodiments, acatheter for pacemaker and ICD (Implantable Cardioverter Defibrillator)lead extraction, the catheter having a tip section comprising: a firstwall having a circular cross section and having a sharp distal edge; anda plurality of optical fibers located along the surface of said firstwall, wherein said plurality of optical fibers are configured totransmit laser radiation configured to modify the tissue surrounding thelead thereby preparing the tissue for penetration of said sharp distaledge of said first wall, wherein said first wall is configured to cutthrough said modified tissue and thereby detach the lead from thetissue.

There is further provided, in accordance with some embodiments, a methodfor pacemaker and ICD (Implantable Cardioverter Defibrillator) leadextraction, the method comprising: using a catheter having a pluralityof optical fibers, transmitting laser radiation towards a tissuesurrounding the lead thereby modifying the tissue and preparing thetissue for penetration of a sharp distal edge of a catheter's wall; andadvancing the catheter over the lead by cutting through the modifiedtissue surrounding the lead and thereby detach the lead from the tissue.

There is further provided, in accordance with some embodiments, acatheter for pacemaker and ICD (Implantable Cardioverter Defibrillator)lead extraction, the catheter having a tip section comprising:circumferentially-directed laser optics; and a circular-action cutter,wherein said circumferentially-directed laser optics is configured totransmit laser radiation for modifying the tissue surrounding the leadthereby preparing said tissue for penetration of said cutter, whereinsaid cutter is configured to cut through said modified tissue andthereby detach the lead from the tissue.

There is further provided, in accordance with some embodiments, a devicefor detaching undesired tissue from an inner wall of a body cavity, thedevice having a tip section in a shape of a cylinder's sector, the tipsection comprising: a plurality of optical fibers located along an innersurface of the tip section and configured to transmit laser radiation tothe undesired tissue; and a cutter having a shape of a cylinder's sectorlocated inwardly and/or outwardly to the plurality of optical fibers,wherein said cutter is configured to cut through the undesired tissueand thereby detach at least a part of the undesired tissue from theinner wall of the body cavity.

There is further provided, in accordance with some embodiments, a methodfor detaching undesired tissue from an inner wall of a body cavity, themethod comprising: using a plurality of optical fibers, transmittinglaser radiation to an area of said undesired tissue, thereby modifyingsaid area; and cutting through said modified area using a cutter,thereby detaching at least a part of said undesired tissue.

In some embodiments, an angle between said device and said endoscope'slongitudinal axis is adjustable according to a required depth of peelingof said undesired tissue.

In some embodiments, cutting comprises rotatably cutting using a bladerotatable along an inner surface of a cylindrical tip section of thecatheter.

In some embodiments, cutting comprises rotatably cutting using anannular blade.

In some embodiments, cutting further comprising vibrating said cutter.

In some embodiments, detaching the undesired tissue comprises peeling ofthe undesired tissue.

In some embodiments, mechanically weakening comprises ablation of saidtissue.

In some embodiments, modifying said area of said undesired depositcomprises mechanically weakening said area.

In some embodiments, modifying said tissue comprises mechanicallyweakening said area.

In some embodiments, modifying said undesired deposit comprisesmechanically weakening said area.

In some embodiments, said circumferentially-directed laser opticscomprises a plurality of optical fibers located along an inner surfaceof the cylindrical tip section.

In some embodiments, said circumferentially-directed laser optics andsaid circular-action cutter are configured to operate simultaneously.

In some embodiments, said circumferentially-directed laser optics andsaid circular-action cutter are configured to operate intermittently.

In some embodiments, said cutter comprises a blade rotatable along saidinner surface of said cylindrical tip section, inwardly or outwardly tosaid plurality of optical fibers.

In some embodiments, said cutter comprises an annular blade locatedalong an inner or an outer surface of the cylindrical tip section,inwardly or outwardly to said plurality of optical fibers.

In some embodiments, said cutter is configured to have two positions, ina first position, the cutter extends further from a distal end of thetip section, and in a second position the cutter is retracted towards aproximal part of the tip section.

In some embodiments, said cutter is configured to shift from the firstposition to the second position when a force above a predetermined valueis applied on said cutter.

In some embodiments, said cutter is configured to shift from the firstposition to the second position upon indication of a force applied onsaid cutter being above a predetermined value.

In some embodiments, said cutter is configured to shift from the firstposition to the second position when a force above a predetermined valueis applied on said cutter.

In some embodiments, said cutter is configured to vibrate.

In some embodiments, said cutter is said catheter's wall, wherein saidwall has sharp distal edges.

In some embodiments, said drug comprises: Elutax®, SeQuent®, Cotavance™with Paccocath® coating technology, TADD (from Caliber Therapeutics,Inc.), Advance® 18PTX®, DIOR®, IN.PACT™ Amphirion, Coroxane or anycombination thereof.

In some embodiments, said laser is a diode pump Holmium Fiber laser.

In some embodiments, said laser is a pulse laser with emitting radiationin the range of 2.8-3 microns.

In some embodiments, said laser is a pulse Thulium laser

In some embodiments, said laser is a pulse Thulium fiber laser.

In some embodiments, said laser is a Er:YAG laser

In some embodiments, said laser is a fiber laser configured to emit at2.8-3 microns.

In some embodiments, said laser is a pulsed laser.

In some embodiments, said laser is a solid state triple Nd:YAG laser.

In some embodiments, said laser radiation is pulsed radiation.

In some embodiments, said one or more lead retraction elements areconfigured to grab the lead only when the catheter is moving outside ofthe body.

In some embodiments, said one or more lead retraction elements comprisea balloon.

In some embodiments, said plurality of optical fibers and said cutterare configured to operate simultaneously.

In some embodiments, said plurality of optical fibers and said cutterare configured to operate intermittently.

In some embodiments, said plurality of optical fibers are configured tomodify an area of the undesired tissue thereby preparing said area forpenetration of said cutter, wherein said cutter is configured to cutthrough said modified area and thereby detach at least a part of theundesired tissue.

In some embodiments, said plurality of optical fibers are located alongan inner surface of said first wall.

In some embodiments, said plurality of optical fibers are located alongan outer surface of said first wall.

In some embodiments, said plurality of optical fibers comprise one ormore optical fibers having a proximal diameter larger than their distaldiameter.

In some embodiments, said second wall comprises a sharp distal edge.

In some embodiments, said tip section is cylindrical.

In some embodiments, said tip section is expandable.

In some embodiments, the catheter further comprises a drug elutingballoon.

In some embodiments, the catheter further comprises a light concentratorat a distal end of said tip section.

In some embodiments, the catheter further comprises a second wall,wherein said plurality of optical fibers are located between said firstand said second walls.

In some embodiments, the catheter further comprises one or more imagingelements configured to provide information on an inner part of saidblood vessel.

In some embodiments, the catheter further comprises one or more imagingelements for monitoring the procedure.

In some embodiments, the catheter further comprises one or more imagingelements configured to provide information on an inner part of saidblood vessel.

In some embodiments, the catheter further comprises one or more leadretraction elements.

In some embodiments, the catheter further comprises one or more openingsfor administering a drug.

In some embodiments, the circumferentially-directed laser opticscomprises a plurality of optical fibers located along an inner surfaceof a cylindrical tip section of the catheter.

In some embodiments, the device further comprises a light concentratorat a distal end of said tip section.

In some embodiments, the device further comprises one or more imagingelements configured to provide information on an inner part of saidcavity.

In some embodiments, the device further comprises one or more openingsfor administering a drug.

In some embodiments, the device further comprises openings or tubing forflushing a cleaning solution.

In some embodiments, the device is configured for use in thegastrointestinal tract, urology or gynecology.

In some embodiments, the device is configured to mount on a tip sectionof an endoscope.

In some embodiments, the method further comprises administering a drugfor preventing or treating restenosis.

In some embodiments, the method further comprises flushing a cleaningsolution.

In some embodiments, the method further comprises imaging the inner partof said cavity.

In some embodiments, the method further comprises imaging the procedure.

In some embodiments, the method is used in endoluminal procedures in thegastrointestinal tract, urology or gynecology.

In some embodiments, the undesired tissue comprises a flat lesion andwherein the gastrointestinal tract cavity comprises an inner wall of thestomach.

In some embodiments, the undesired tissue comprises a flat lesion andwherein the gastrointestinal tract cavity comprises an inner wallsurface of the stomach.

In some embodiments, the undesired tissue comprises a sessile polyp,flat polyps and NP-CRN (Nonpolypoid colorectal neoplasms) and whereinthe gastrointestinal tract cavity comprises an inner wall surface of thecolon.

In some embodiments, the undesired tissue comprises Barrett's tissue andwherein the gastrointestinal tract cavity comprises the esophagus,wherein said tip section is configured to match the typical anatomy ofthe esophagus.

In some embodiments, the undesired tissue comprises Barrett's tissue andwherein the gastrointestinal tract cavity comprises the esophagus.

In some embodiments, transmitting laser radiation and cutting areconducted simultaneously.

In some embodiments, transmitting laser radiation and cutting areconducted intermittently.

BRIEF DESCRIPTION OF THE FIGURES

Exemplary embodiments are illustrated in referenced figures. Dimensionsof components and features shown in the figures are generally chosen forconvenience and clarity of presentation and are not necessarily shown toscale. The figures are listed below.

FIG. 1A shows an exemplary cylindrical tip section of a hybrid catheterin perspective view;

FIG. 1B shows an exemplary cylindrical tip section of a hybrid catheterin a front view;

FIG. 1C shows an exemplary cylindrical tip section of a hybrid catheterinside a vessel with partial plaque blockage in a cross-sectional view;

FIG. 2 shows an exemplary tip section of a hybrid catheter, with one ormore alterations with respect to FIGS. 1A-C.

FIG. 3A shows a tip section which includes a hollow reflective lightconcentrator;

FIG. 3B shows a tip section which includes a solid-state lightconcentrating waveguide;

FIGS. 3C-3E show the usage of tapered fibers;

FIGS. 4A-4B show a circular-action cutter;

FIG. 5 shows a cross-sectional view of an expandable tip section;

FIGS. 6A-B illustrate a tube 600 introduced through the catheter andending with an array of nozzles or apertures

FIGS. 7A-B illustrate the use of a roller 700 to stain the tissue

FIGS. 8A-B illustrate apertures 800 built into the catheter's housing

FIGS. 9A-B illustrate an array of tubes or needles 900 a-b which areused to administer the drug

FIG. 10 shows an exemplary tip section of a hybrid device mounted on anendoscope;

FIG. 11 shows a hybrid catheter mounted on an endoscope, during aprocedure of detaching undesired tissue;

FIG. 12 shows a catheter assembled on a commercially-availableendoscope; and

FIGS. 13A-13C show a cross section of a hybrid catheter over a lead tobe extracted.

DETAILED DESCRIPTION

An aspect of some embodiments relates to a hybrid catheter and methodsfor using the same in endoluminal interventions. For example, presentembodiments may be useful in various vascular applications, such asatherectomy, angioplasty, debulking of plaque in in-stent restenosis,leads extraction, thrombectomy in chronic peripheral and coronary arterydiseases and for management of acute blockage of vessels in coronary andneurovascular applications. Another example is the use of embodiments ingastroenterology, such as for removal of sessile and flat lesions in theGI track, Barrett's Esophagus management and in analogous applicationsrequiring removal of tissue from the inner walls in gynecology andurology interventions.

The hybrid catheter may be based on a combination of laser andmechanical removal (also “debulking”) of an undesired material from abodily lumen. In vascular interventions, the catheter may be configuredto weaken and/or even cut and detach undesired material with a laser andthen, even in cases where the plaque material was not entirely removed,detaching the rest of the plaque material by mechanical means, such asusing a blade. The laser may change the mechanical characteristics oftissue, and thereby improve performance of mechanical tools such asvarious types of blades or shavers. By way of example, the laser maymake a soft tissue crispier so it can be effectively crushed using themechanical tool.

Advantageously, usage of the present catheter may obviate the need tophoto-ablate (evaporate) most or all of the undesired material.Accordingly, the process may be faster and result in lesser by-productsthan in common laser ablation, lesser associated mechanical stress andlesser other side effects such as thermal injury resulting from photoablation. The process may allow using smaller lasers wherein energy isfocused at a smaller area and wherein mechanical tools remove tracesremaining in the treated area and facilitate further penetration of thelaser beam to proceed in effective ablation. In addition, challengingcalcified tissue may be successfully treated, despite the difficulty inmany of today's common mechanical or excimer lasers to delicately detachsuch tissue from the vessel's walls. The present catheter,advantageously, provides for controlled cutting of plaque with minimalor no damage to the vessel's walls.

This hybrid catheter disclosed herein may be used (for example inatherectomy) alone and/or in conjunction with low pressure balloonangioplasty, stenting, for treating in-stent restenosis with no damageto the stent, and/or for treatment of acute blockages due to plaques andor thrombus (thrombectomy).

The terms “cut”, “dissect”, “resect”, “detach”, “debulk” and “remove”may be used here interchangeably.

According to some embodiments, the catheter comprises a tip section,which may be essentially in a cylindrical shape, havingcircumferentially-directed laser optics, optionally in the form of oneor more optical fibers, configured to deliver laser radiation, and acircular-action cutter including one or more blades configured to assistin cutting and/or detaching undesired materials (also “deposits”) froman inner surface of a blood vessel. The one or more optical fibers maybe circumferentially-directed, namely, they may be located along aninner surface of the cylindrical tip section, which is near theperiphery of the tip section. Alternatively, thecircumferentially-directed optical fibers may be located elsewhere butdirected, by way of orientation and/or optical focusing, to radiate anarea in front of the circumference of the tip section.

The circular-action cutter may be located in a central part of the tipsection, for example, surrounded by the optical fibers. Alternatively,the circular-action cutter may be located in the periphery of the tipsection and the one or more optical fibers are located in a central partof the tip section, for example, surrounded by blades.

According to some embodiments, the one or more optical fibers and theone or more blades are located in the periphery of the tip section.

According to some embodiments, the one or more optical fibers and theone or more blades are located in a central part of the tip section.

According to some embodiments, the circular-action cutter lays on aspring so that a maximum force applied by the cutter is predetermined inorder to avoid potential damage, yet be effective. The tip section mayinclude an inner channel maintained at a relative low pressure to suckthe undesired material which may be plaque, thrombus material, debris,saline solution used for cleaning and/or the like.

Optionally, a motor is provided to rotate the circular-action cutter inorder to improve fragment cutting and/or detaching. Additionally oralternatively, the motor or a different motor may be used to rapidlyvibrate the circular-action cutter in order to improve fragment cuttingand/or detaching.

Optionally, the circular-action cutter is heated to improve itsperformance. This may be done by an external heat source, electricalmeans and/or by the laser radiation.

According to some embodiments, the catheter tip may be expandable, suchthat its diameter may be increased after its introduction into thevessel.

According to some embodiments, the catheter tip may include means fordeflection, such that effective working area will be larger than thecatheter diameter and enable off-axis work.

According to some embodiments, the catheter may be useful in cases ofChronic Total Occlusions (CTO), where a guidewire cannot normally beused to pass lesions totally blocking the vessel, and thereforeatherectomy is often not feasible, since usage of a guidewire oftendictates a certain relative position, and angle in particular, of thecatheter's tip section versus the vessel.

An example of an appropriate laser of some embodiments is a solid stateultraviolet (UV) laser emitting pulses in approximately 355 nm and/or266 nm. An example of an appropriate laser is the Qauntel CFR400,emitting 50 mJ, 10 ns pulses of 355 nm at 50 Hz and/or 40 mJ of 266 nmat 40 Hz. Another example is an Excimer laser.

In case of using significantly high repetition rates, thermal effects inthe tissue may become a problem. This can be at least partially resolvedby minimizing ablation area (depth and width), use of short laser pulsesand with saline flushing. Another option includes sequentialillumination of fibers in a manner that not all the fibers are exposedto laser ration simultaneously, in order to enable thermal relaxation ofthe affected tissue.

In an embodiment, dyes or substrates may be used to enhance absorptionat certain wavelengths, such as 355 nm. For example, sensitization withhaematoporphrin or tetracycline prior to the procedure, in order toenhance ablation of the pretreated atheromatous plaque but notinsensitised or normal arterial wall.

Another example of a laser of some embodiments is a laser emittingpulsed radiation in the mid-infrared (IR) region, such as in the rangeof 2.8-3 micrometers, a range where water is very effectively absorbed.Additionally or alternatively, radiation at around 2 microns may beused, with a preference for thulium laser emitting at 1910-1940 nm rangewherein there is higher absorption of water preferably combined withQ-switched modulation wherein ablation is more effective and reduceslateral damage. For 3 micron emission, an Er:YAG may be used, or anothersource such as a Mid-IR Holmium Fiber Laser Directly Pumped with DiodeLaser that emits at 2840 nm using fluoride fibers [see Optics Letters,Sep. 1, 2007, pp. 2496-2498].

Yet another example is usage of a third harmonic of a Nd:YAG laser at355 nm, preferably a compact, all solid state, diode pumped laser. The355 nm radiation usually has a deeper penetration capability compared tothe 308 nm radiation, in the depth range of 100 micron or more inrelevant tissues and materials. Optionally, very short pulse widths(such as <10 ns) are used, in order to obtain a higher power density,and, in particular, to be able to ablate calcified plaques. Inaccordance with some embodiments, the energy per pulse is in the rangeof 10-100 mJ and the pulse frequency is in the range of 10-100 Hz.Optionally, the area of ablation may be flushed with a saline solutionin order to reduce side effects (such as cavitation), clean the area ofablation and catheter and/or facilitate collection of debris.

One of the advantages of using 355 nm radiation is that is consideredrelatively nonmutagenic. The 308 nm radiation of the xenon chloridelaser is in the UVB range, which is known to have mutagenic risks.[Walter Alexander. Journal of Clinical Laser Medicine & Surgery. August1991, 9(4): 238-241. doi:10.1089/clm.1991.9.238.]

Some prior studies have indicated that third harmonic lasers aregenerally less suitable to endovascular interventions than 308 nmlasers, due to longer penetration rates and reduced effectiveness ofablation (see, for example, Grundfest W S et al., Am J Surg. 1985August; 150(2):220-6; and Frank Laidback et al., Lasers in Surgery andMedicine 8:60-65 (1988)). The present embodiments, however, maysuccessfully utilize third harmonic Nd:YAG lasers instead of complex andexpensive Excimer lasers. The present embodiments address severalproblems. For example, in some embodiments, it may not be necessary tolaser-ablate all the material whose removal is desired, but rather thelaser and the mechanical cutter may share the task; the laser may ablateand/or weaken at least some of the material, while the mechanical cuttercompletes the job by finally detaching the material from the walls.

In some embodiments, a laser that emits radiation in 266 nm may be used.This wavelength has a shorter penetration rate in addition use ofcompact Excimer laser emitting radiation at 308 nm, as currently used,can be utilized with the current embodiments. According to someembodiments, a system may include means that enable an operator toswitch between 266 nm and 355 nm, generated from the same Nd:YAG laser,and means to control power, repetition rate and/or exposure/illuminationof specific fiber groups.

An alternative embodiment of the present invention replaces UV laserswith a laser with radiation in the 2 micron or 2.8-3 microns, in whichablation is very effective.

Holmium lasers are conventionally used for 2 microns but Thulium lasershave a stronger water absorption and smaller absorption length, whichmakes them especially suitable for some embodiments. For example, in anembodiment, pulsed fiber thulium laser is used. Alternatively, a solidstate laser may be used in order to increase pulse power per pulse,which is currently limited in fiber lasers and in view of the limitedpulse rate that can be used in order to minimize heat accumulation anddamage.

Laser in 2.8-3 micrometer may be Er:YAG. Er:YAG Q-switched are availablewith pulses in the hundreds of nanosecond range, which may be suitablefor present embodiments. See, for example, M. Skorczakowski, et al,Laser Physics Letters Volume 7, Issue 7, pages 498-504, July 2010.Another laser example which may be suitable for specific embodiments isPantec's model DPM-15 solid state laser, emitting microsecond pulses inthe mJ range at hundred of KHz.

In an embodiment, fiber lasers which may be directly diode-pumped, suchas a Mid-IR Holmium Fiber Laser, are used. This laser may be pumped fromground level (⁵I₈) to an excited energy band (⁵I₆) with radiation atabout 1150 nm, and the relaxation bands may lead to emission at 2840 nm(relaxation to band ⁵I₇) and 2100 nm in relaxation to ground state.Accordingly, this laser may be directly pumped with recently developedhigh-power, high-brightness diode lasers based on highly strained InGaAsquantum wells that produce output at 1148 nm. See Optics Letters, Sep.1, 2007, pp. 2496-2498 and Stuart D. Jackson Optics Letters, Vol. 34,Issue 15, pp. 2327-2329 (2009).

The laser may be selected according to the selected resonator optics,for example fluoride fiber lasers to emit laser radiation on the 2.9-μmtransition (516 to 517) and silica fiber lasers to emit radiation on the2.1-μm transitions (517 to 518). An advantage of an embodiment using alaser in the region of 2.9-3 micron is that the absorption is very highand results in very short length of absorption, in the order of 15microns only. Therefore, the relaxation time is shorter so the pulserate may be increased to above 100 Hz in order to accelerate theprocedure.

In addition to the laser beam that interacts with the undesiredmaterial, a laser with controlled pulse rate and/or power may be used tointeract with the liquid between the fiber tip (exit of laser beam) andtissue, either to allow for “opening” of a passage for the beam (e.g., achannel wherein light is not absorbed when UV radiation is used) to thetissue prior and adjunctive to the required interaction with the tissue,and/or to facilitate the process (when mid-IR radiation is used)benefiting from the “water spray” effect. By way of clarification thetip can be in mechanical contact with the tissue being ablated or not.

Reference is now made to FIGS. 1A, 1B and 1C, which show an exemplarycylindrical tip section 100 of a hybrid catheter in perspective, frontand cross-section views, respectively, in accordance with an exemplaryembodiment. The remainder of the catheter's shaft (not shown) may, insome embodiments, be biocompatible polymer tubing, optionally coated, tominimize friction with the vessel's walls.

Tip section 100 is positioned at the distal end of the hybrid catheter,the end which is inserted into the blood vessel. Tip section 100 mayinclude a housing 102, for example a cylindrical one, at least one opticfiber(s) 104 positioned along an inner surface of housing 102, and acircular-action cutter (or simply “cutter”) 106 positioned inwardly ofthe optic fibers. Alternatively, in an embodiment (not shown), thecircular-action cutter may be positioned outwardly of the optic fibers.It is intended that the following description of the embodiments inwhich the circular-action cutter is positioned inwardly, be applied,mutatis mutandis, to the alternative, not-shown embodiment. Optionally,optic fiber(s) 104 are delimited and/or supported by a first inner wall108. Further optionally, cutter 106 is delimited and/or supported by asecond inner wall 110.

In accordance with some embodiments, the catheter is used with astandard guidewire.

In accordance with some embodiments, the catheter is connected to asuction pump that generates low pressure to collect undesired material,saline and/or the like through the catheter. The pump may be aperistaltic pump, which mounts externally to the fluid path, to avoidany contamination of the pump. Optionally, this obviates the need to usedisposable parts.

Optic fibers 104, serving as the laser optics of the present hybridcatheter, may be connected, at their proximal end (not shown) to a lasersource characterized by one or more of the parameters laid out above.Optic fibers 104 may deliver the laser beams from the source towards theintervention site in the body. In tip section 100 of FIG. 1C, opticfibers 104 are shown as they emit laser towards undesired material 114.One or more areas 116 in undesired material 114 may consequently bemodified or even ablated by the laser. Then, cutter 106 may more readilycut into undesired material 114 and detach at least a part of it fromthe vessel's walls 118.

Cutter 106 is optionally an annular blade extending to a certain depthinside tip section 100 and coupled to a suitable motor (not shown),located in the tip section or further in the shaft, supplying rotaryand/or vibratory power to the blade. Optionally, one or more flexiblemembers, such as a spring 112, may interact with cutter 106 at its base,to allow it to retract and protrude from housing 102. Tip section 100 ofFIGS. 1A-C is shown with cutter 106 in its protruding position, whiletip section 100 b of FIG. 1C is shown with the cutter, now marked 106 b,in its retracted position. The length of protrusion out of housing 102may be, for example, up to about 350 microns when treating bloodvessels. When protruding, cutter 106 is used for detaching undesiredmaterial (also “deposit”) 114 from an inner surface 118 of a bloodvessel 120. According to some embodiments, when a certain force (forexample, above a predetermined value) is applied to cutter 106 from thefront, which may be a result of blockage in blood vessel 120, the cuttermay shift its position and retract into housing 102.

The annular blade of cutter 106 may have sufficiently thin edges, suchas around 100 microns. Suitable blades may be tailor-made by companiessuch as MDC Doctor Blades, Crescent and UKAM. The blade may optionallybe mounted at the end of a rotatable tube rotated. Such tubes areavailable from manufacturers such as Pilling, offering a line of laserinstrumentation and blade manufacture. The blade may be metal ormanufactured by molding a material such as plastic which is optionallycoated with a coating having proper characteristics for in-vivo use.

An exemplary tip section may have an external diameter of approximately5 mm, an internal diameter (within the innermost layer, be it the cutteror an extra wall) of approximately 3.4 mm, and optical fibers eachhaving an approximately 0.1-0.2 mm diameter.

Reference is now made to FIG. 2, which shows an exemplary tip section200 of a hybrid catheter, which may be similar to tip section 100 ofFIG. 1 with one or more alterations: First, one or more fibers 222 ofthe optical fibers existing in tip section 200 may be used for imagingthe lumen of a blood vessel 220 by transporting reflected and scatteredlight from inside the lumen to an external viewing and/or analysisdevice (not shown) located externally to the body. This may aid inavoiding perforation of vessel 220 and allowing for on-line monitoringof the intervention process. Second, tip section 200 may bemaneuverable, so as to allow different viewing angles and/or in order toalign the laser beams and a cutter 206 differently. Third, a cleaningchannel (not shown) may be present inside tip section 200 and extendingoutside the body, through which channel suction 224 is applied in orderto evacuate debris of the undesired material which were treated by thelasers and/or cutter 206. These optional alternations are now discussedin greater detail:

A conventional manner for detection of plaque and other lesions and formonitoring of vessel treatment is based on ultrasound and fluoroscopy.Here, however, one or more fibers 222 may be utilized for detection oflesions and/or to monitor the intervention process on-line, based on thereflection and/or scattering of the laser light from the vessel and/orthe deposits. Alternatively or additionally, a different source ofillumination may be used, such as through one or more other fibers. Thecaptured light may be transmitted to a sensor such as a CCD, a CMOS or aMOS. The sensing may include a filter or means for spectral imaging, togain information about the material characteristics (plaque, tissue,calcified plaque, blood clot, etc.). This may enable a quick andeffective procedure with minimal risk of perforation, and may enabledebulking procedures wherein a guidewire cannot or should not be used.

The angle of tip section 200 may be controlled to enable by means of tipdeflection material removal in a cross-section larger than the cathetersize. This may be done by mechanical means, such as by selectiveinflation and deflation of at least two balloons (not shown) attached tothe tip section externally at different angles, or a balloon withdifferent compartments 226 a-d. Another example is usage of linksforming a joint 228, controllable from outside the body using one ormore wires (not shown).

The laser optics of some embodiments will now be discussed in greaterdetail. The laser beam may be directed through fibers each having a corediameter optionally in the range of 40-250 microns. In a configurationwhere the catheter's circumference is, for example, 15 mm, using fiberswith an outer diameter of 50 microns will result in using approximately300 fibers with a cross-section area smaller than 1 mm², so that for acoupling efficiency of 75%, the energy at the exit of each fiber will beclose to 40 mj/mm when pumped with a 50 mJ laser. Adequate fibers forsome embodiments may be all-silica fibers with a pure silica core. Thesefibers can usually withstand about 5 J/cm² in the input. Someembodiments include fibers with a numerical aperture (NA) in the rangeof 0.12-0.22. An example of a relevant fiber is FiberTech Optica'sSUV100/110AN fiber for UV application and the low OH versionSIR100/140AN for use with laser in the 1900-2100 nm range or InfraredFiber Systems, IR Photonics and A.R.T. Photonics GmbH fibers fortransmission of radiation in the 2900-3000 range. Embodiments of singlemode or multimode may be realized while preservation of beam quality isimportant but not mandatory in certain embodiments. Some embodiments mayinclude microlenses at the tip area to manipulate the beam at eachindividual fiber exit.

The power required for effective ablation with 355 nm, 10 nsec pulses(approximately 30-60 mJj/mm²) is close to the damage threshold ofcertain fibers or above it, which lead, in existing products, to theneed of extended pulse length, for example. According to someembodiments, high peak power is maintained and accordingly the cathetermay include means for delivery of the laser power through relativelybigger optical fibers, e.g. 100 or even 300 micron fibers that do notextend all the way to the end of the tip section, as schematicallyillustrated in FIGS. 3A-3E.

FIG. 3A shows a tip section 300 which includes a hollow reflective lightconcentrator 304 a with a straight profile or a concave profile (asshown), used to concentrate light from at least two fibers (shownjointly at 304). Hollow concentrator 406 a may have metal-based ordielectric coating. Hollow concentrator 304 a may form a ring shapesurrounding a cutter 306, in manner that radiation from all the fibersis delivered with one concentrator, so that a relatively uniform ring ofpulsed radiation is generated at the exit. The exit may include a window(not shown in the figure). Optionally, the optical path may bemaintained clean with flushing of saline. Flushing may be through anopening in the front or from the side, between the catheter and an extralumen that can also facilitate catheter movement in the vessel or incertain embodiments through the central lumen.

FIG. 3B shows a tip section 330 which includes a solid-state lightconcentrating waveguide 334 a for concentrating light from at least twofibers (shown jointly at 304). Solid-state waveguide 334 a may be made,for example, of Silica with a reflective coating, or a combination oftwo materials such as Silica and Fluoride-doped Silica.

Solid-state waveguide 334 a may be optically coated at the interfacewith the fiber(s), to improve optical throughput from the fiber(s) tothe concentrator. Alternatively, the two may be welded.

FIGS. 3C-3E illustrate the usage of tapered fibers, such as thoseavailable from Oxford Electronics. The fibers may be thick 340 at theproximal end of the catheter's shaft, and thin 342 at its distal end—asseen in cross-section. FIG. 3E shows a single tapered fiber 340 a inperspective view.

Reference is now made to FIG. 4A, which shows another option for acircular-action cutter, in accordance with an embodiment. Thecircular-action cutter here may be a rotating blade 406 which isrotatable, for example, using a flexible shaft 460 which centrallyrotates a plate 462 peripherally connected to the rotating blade.Flexible shaft 460 may be capable of delivering a limited amount oftorque, especially when there is bending in the artery, etc. Commonmechanical atherectomy devices sometimes use very high rotation speedsto compensate for that. Present embodiments reduce the need for highmoments, as the blade is active in an area which has been prepared,namely—cut or at least modified by the laser. Furthermore, the fact thatlower torque and rotating forces are applied to the atheroma/plaques,decreases the radial forces applied to the vessels.

Reference is now made to FIG. 4B, which is mostly similar to FIG. 4A,except for the way rotating blade 406 is being rotated. Rotating blade406 may be rotated by a miniature motor 464 and suitable transmission466. Appropriate miniature motors are available from manufacturers suchas Namiki, which developed a 1.5 mm-diameter micro-geared DC motor.

Optionally, rotating blade 406 of FIGS. 4A-4B may have shapes thatfacilitates collection and/or scraping of debulked material, tofacilitate collection of debris.

In order to enable effective debulking in blood vessels, catheters ofdifferent dimensions may be used, for example in the range of 4-22French (approximately 1.3-7 mm). The use of a larger catheter holds theadvantage of enhancing the intervention process, but raises an issue ofa large opening required for introduction into the vessel and/oraccessibility within the vessel itself. Therefore, according to someembodiments, the diameter of the catheter, at least at its tip section,may be expandable. A first example is shown in FIG. 5, which is across-sectional view of an expandable tip section 500. A housing 502 oftip section 500 may be made of a relatively flexible material, comparedto the rest the catheter's shaft. When the catheter reaches thedebulking site, tip section 500 is expanded, to form anoutwardly-tapered shape. This expansion may be achieved by introducing amechanical element which applies pressure on one or more parts in tipsection 500. Fibers 504 that transmit the laser beam, may then beinserted into the catheter's walls. Since when the tip section 500 isexpended the distance between the fibers also extends, more fibers maybe inserted into the walls. Optionally, the mechanical elementintroduced to expand tip section 500 includes cutter 506. Optionally,expandable tip section 500 may be used in conjunction with the tipsection deflecting means of FIG. 2.

In another embodiment of a catheter with an expandable tip section,materials with shape memory, such as Nickel Titanium (known as Nitinol),may be used. The catheter, or at least its tip section, is compressedbefore introduction into the body, and naturally returns to itspre-compressed shape after it is introduced to the lumen. Nitinol may beused in a structure of a mesh or a braid, to provide sufficient radialforce while enabling contraction with low enough radial forces when thecatheter is retracted. Some flexibility may still remain at the tipsection, to allow accommodation to the physiological shape of lumen. Thetip may also include means for controlled deflection.

In some embodiments, the catheter may perform local delivery of drugswhich reduce the incident of restenosis, such as Paclitaxel and itsderivatives, or soluble forms such as Coroxane. The drug may remain inthe site post-treatment and assist in lumen recovery, while preventingoverdosing and systematic effects.

The drug administration following the removal of undesired material fromthe vessel or stent may be achieved by means such as: (i) spraying ofdrug from nozzles in the external surface of the catheter, or with atube that includes an array of nozzles at its end, threaded through asuitable channel in the catheter; (ii) by a roller that “paints” thetissue; (iii) by a drug-coated balloon; (iv) by a balloon that includesmeans to deliver drug through channels in its wall; (v) brushes in thecatheter walls; (vi) tubes with nozzles which may change their directionon the way in and out the material removal site.

To optimize long-term efficacy, some embodiments provide means for deepadministration of the drug, to be sustained in the deeper layers of thearterial wall or even in remaining plaque but not in the endothelium,thereby allowing new endothelial cells to grow and re-align the lumen,to inhibit restenosis in deep cell layers after the lumen has beenrestored and re-endothelialized. This may be accomplished by means suchas pressure-controlled drug administration, administration below thesurface and/or selection of adequate drug forms.

In order to increase absorption of plaque material, the treatmentprocedure may include administration of one or more substances thatincrease absorption of plaque at 335 nm such as treating withtetracycline for which the uptake by plaque is a few times larger thanin normal tissue. See, for example, Murphy-Chutorian D, et al, Am JCardiol. 1985 May 1; 55(11):1293-7.

For blood vessel treatment, it is often desired to administer the drugin the deeper layers of the arterial wall but not in the endothelium,thereby allowing new endothelial cells to grow and re-line the lumen. Asa result, the drug continues to inhibit restenosis in deep cell layersafter the lumen has been restored and re-endothelialized, while, on theother hand, overdosing and systematic effects are eliminated. In some ofthe cases some plaque material remains on the vessel's walls or stentand the drug formulation and means of administration should take it inaccount.

Examples of applicable drugs include: Elutax®, SeQuent®, Cotavance™ withPaccocath® coating technology, TADD (from Caliber Therapeutics, Inc.),Advance® 18PTX®, DIOR®, IN.PACT™ Amphirion, Coroxane and more.

The conventional way to administer these drugs to avoid restenosis iswith coated balloons. Alternative drug forms such as Coroxane may beadministered via IV promptly after the procedure, but this would notresult in local administration. It has been suggested in the literatureto perform a two step process wherein a coated balloon followsatherectomy, but this would result in a more complex and costlyprocedure that can limit routine clinical use.

FIGS. 6A-B, 7A-B, 8A-B and 9A-B include schematical illustrations of anumber of exemplary tip section embodiments suitable for localadministration of drugs.

FIGS. 6A-B illustrate a tube 600 introduced through the catheter andending with an array of nozzles or apertures 602 that spray the drug ondemand.

FIGS. 7A-B illustrate the use of a roller 700 to stain the tissue. Thecatheter may include means to allow the roller to get at least partiallyinside a groove 702 before the debulking procedure, and exit the groovewhen needed to transfer the drug to the tissue. Roller 700 may includemeans to apply pressure to the walls in order to increase drug deliveryand/or expand the stent in in-stent restenosis (ISR) applications.

FIGS. 8A-B illustrate apertures 800 built into the catheter's housing,and configured to be opened only when needed.

FIGS. 9A-B illustrate an array of tubes or needles 900 a-b which areused to administer the drug in a manner that will increase itssustainability. Means to allow the angle of the tubes relative to thecatheter to change before and after the debulking procedure and/or inthe way inside and outside from the lumen/stent are provided. The tubesmay be facing forward 900 a when moving forward and backwards 900 b whenmoving backwards. The tubes are optionally made of a flexible,biocompatible material.

Further examples of drug administration may include: a brush to transferthe drug through nipples in the wall of the catheter; a balloon foradministration of drug; a balloon surrounding the catheter and beingcoated with the drug and inflated after the debulking procedure; aballoon with nipples that are used to administer drug on demand; and acoated balloon inserted through the cleaning channel of the catheter.

The embodiments disclosed herein are brought as examples and can becombined for the purpose of vascular intervention in peripheral,coronary and neurovascular applications in chronic and acute conditionsand in other medical applications wherein stents have to clean such asin gastro and urology and in applications wherein lumens have to becreated or extended such as Benign Prostatic Hyperplasia.

Another clinical application, according to some embodiments of thepresent invention, is in removal of undesired tissue from a body cavityduring an endoluminal procedure. Such procedures can be performed forexample in gynecology, urology and in gastroenterology. Such proceduresmay include, for example, removal of flat and/or large lesions in thegastrointestinal (GI) track and in management of Barrett's esophagus.The motivation is to remove the undesired pathological tissue withminimal complications (e.g., in case of Barrett's esophagus, withoutesophageal perforations and strictures). This clinical application mayrequire modified embodiments of the hybrid catheters disclosed herein inaccordance with some embodiments. FIG. 10-FIG. 12 illustrate cathetersfor detaching undesired tissue from an inner wall of a body cavity, forexample, but not limited to, Barrett's esophagus management, accordingto embodiments of the invention.

The first embodiment is a hybrid catheter which combines a utility oflaser radiation to ablate and cut/detach the undesired pathologicaltissue or modify its mechanical characteristics and mechanical meanssuch a blade or a sharp edge of a wall of the catheter to complete thedetaching. This way, the tissue is resected/disected using the laserradiation and the blade/wall's edge. Thus the blade/wall's edge does notneed to be too sharp and are thus configured to cut the tissue withoutthe risk of potential perforation or damage to the body cavity.

Reference is now made to FIG. 10, which shows an exemplary tip section1000 of a hybrid device in perspective view, mounted on an endoscope1500, in accordance with an exemplary embodiment. The remainder of thecatheter namely—its shaft (not shown) may, in some embodiments, bebiocompatible housing, optionally coated so as to reduce friction withthe cavity's wall. Endoscope 1500 may be any commercially availablescope having, inter alia, working channel 1502, for insertion of medicaltools, water/air injector(s) 1504 for cleaning and insufflation, andilluminators 1506. Endoscope 1500 may also include a camera 1508including CCD, CMOS or MOS sensors for example and optics.

Tip section 1000 is positioned at the distal end of the hybrid catheter,the end which is inserted into the body cavity such as the esophagus.Tip section 1000 has a shape of a sector of a cylinder and is generallyconfigured to be mounted on top of an endoscope (for example, as used inupper endoscopy or colonoscopy). The shape of tip section 1000 is alsoconfigured match the typical anatomy of the body cavity to which it isintended to be inserted. Of course, the tip section of the hybridcatheter (device) may have other appropriate shapes and forms, and canmounted in certain embodiments on another working tool that is used tomanipulate it while the process is monitored with another camera such asin laparoscopic procedures. Tip section 1000 may include two walls, anexternal wall 1002 and an internal wall 1004. One of the walls (externalwall 1002 and an internal wall 1004) or both of them may have sharpdistal edges to facilitate cutting through the undesired tissue. One ofthe walls (external wall 1002 and an internal wall 1004) or both of themmay be coated with a material that provides sharper edges. At least oneoptic fiber(s), typically a plurality of optical fiber(s) 1006 arepositioned between external wall 1002 and an internal wall 1004.Alternatively, in an embodiment (not shown), there may exist only onewall and the optic fibers may be located along an internal or anexternal surface thereof. Alternatively, in an embodiment (not shown),there may exist a cutter (similar to the cutter shown in FIGS. 1A-C onlyhaving a shape of a sector of a cylinder). In another embodiment,external wall 1002, an internal wall 1004 and/or a cutter (blade) mayhave two positions, retracted position and protruded position(configured for cutting).

The external wall 1002, an internal wall 1004 and/or a cutter (blade)are configured (such as by virtue of sharpness) to cut through theundesired tissue and thereby detach at least a part of the undesiredtissue from the inner wall of the body cavity. If a blade is present, itmay be a rotary-action blade and/or a vibrating blade. According to someembodiments, optical fibers 1006 are configured to transmit laserradiation configured to modify an area of the undesired tissue therebypreparing said area for penetration of external wall 1002, an internalwall 1004 and/or a cutter (blade).

According to some embodiments, the blade may be mounted in a spring sothat when force is applied beyond a certain predetermined level theblade enters into its compartment (shifts to retracted position).Alternatively, in another embodiment the position of the blade may becontrolled by a physician. This way, the blade is not sharp enough tocut the tissue without the laser so as to avoid potential perforation.Flushing of saline or another appropriate solution at the edge of thecatheter may be used to maintain an optical clean path, removeunnecessary material and reduce potential thermal damage and use a“water spray” effect with mid-IR radiation sources.

Reference is now made to FIG. 11, which shows a hybrid catheter mountedon an endoscope, during a procedure of detaching/resecting (“peeling”)an undesired tissue, according to some embodiments. Hybrid catheter 1001includes a tip section 1000, transmitting laser radiation and cuttingthrough the tissue. In this figure, hybrid catheter 1001 is used toremove the Barrett's tissue 1008. The illustration shows that differentlayers can be targeted and removed. Barrett's tissue 1008 (or any otherundesired tissue) is cut by catheter and lifted. The catheter, such ascatheter 1001, may be (not necessarily) assembled on a commerciallyavailable endoscope, such as endoscope 1600 (FIG. 12). According to someembodiments, the tip section of the hybrid catheter (particularly butnot limited to) in interventions in the GI track may be position inpredetermined angle versus the scope axis and thereby predetermining thedepth of penetration of the tip according to the peeling depth required.

“Peeling” like mode can be thought of in analogy to a “carpenter plane”but using a “hybrid blade”. The depth of peeling can be adjustedaccording to the clinical condition such as the depth for Barrett'sremoval or required according to the stage of the disease and similarlyin flat lesion in other places of the GI track. Accordingly the positionof the blade knife can be adjusted as well as the distance between theblade and the plane. The catheter with a hybrid blade can be located ata predetermined angle/position and distance from the plane of theendoscope or another tool used to hold the tip. In this embodiment thatcatheter can be used to make the initial incision of the tissue as a fewlaser pulses are used to enable generation of a cut to allow the bladeto cut through the required layers and then followed by movement of thecatheter with the help of the scope over the organ in forward orbackwards direction according to the position angle of the catheter.

In accordance with some embodiments the catheter is inserted through theworking channel of a standard endoscope or through a special openingmade in a dedicated scope. Some embodiments include using a tip with amemory shape that is contracted for introduction through the workingchannel and is expanded when it exits the endoscope tip. Such a cathetermay be based on use of Nitinol. These embodiments enable the physicianto perform a diagnostic procedure and, if a pathology is found, tointroduce the resection catheter.

In another embodiment depending on the pathology the laser wavelengthcan be selected to enable reduced tissue penetration or surface ablationsuch as in 355 nm or 2.8-3 microns lasers or deeper with the 266 nmlaser. For below the surface tissue interaction an embodiment of theinvention includes a use of a mid-IR laser which had a longerpenetration depth. A Thulium laser (potentially a Thulium fiber laser@lambda=1908-1940 nm, wherein wavelength is matched according to theembodiment to compensate for water absorption wavelength changedepending on temperature) may be used for this application since it hasa better matching with water absorption length around 2 microns comparedto Holmium:YAG and accordingly penetration depth is limited to a fewhundred microns and also pulse rate can be increased comparing toHolmium without thermal damage.

One of the potential advantages in using the “hybrid catheter” fordebulking of required tissue from lumens such as in the GI track is theside effect of the laser and this is enhancing homeostasis and avoidbleeding. Depending on the specific laser used the effect may not besufficient to avoid bleeding and some embodiments may include use of anadditional laser for the purpose of hemostasis preferably deliveredthrough the same optical fibers.

In accordance with some embodiments, the catheter is connected to asuction pump that generates low pressure to collect undesired material,saline and/or the like through the catheter. The pump may be aperistaltic pump, which mounts externally to the fluid path, to avoidany contamination of the pump. Optionally, this obviates the need to usedisposable parts.

The hybrid catheter blade can also be used for improved biopsyprocedures enabling relative large sample to be collected for furtherhistology analysis and thereby decrease sampling errors, which areassociated with high risk in patients with BE or in gynecology andurology applications.

According to some embodiments, the hybrid catheter may further includeimaging means to detect the required area that has to be treated and tomonitor the process on-line, thereby enabling effective “focal therapy”according to the diseases severity from early stage such as Barrett'sesophagus without dysplasia to more advanced disease with minimalcomplications, as it limits damage to the surrounding healthy tissue andavoid mucosal perforation. Similar considerations may apply ingynecology and urology applications. Means to obtain images of theworking area may include, for example, commercial fiberscope such MeditINC F2.4 (2.4 mm 45 degrees FOV, with 30,000 pixels) or Olympus LF-2(designed for tracheal intubation) that can be inserted into 5 mm tubesand includes a 1.5 mm channel for easier aspiration/instillation offluids, providing images with 90 degrees field of view from >3 mm so thefiber can be placed accordingly. As disclosed hereinabove, the hybridcatheter may be combined with a commercial endoscope, such as agastroscope preferably such that has enhanced imaging capabilities sucha narrow band imaging (NBI) to detect the pathological areas with higherresolution. For example, an Olympus GIF-H180J model (or equivalent) maybe used, which has a 9.9 mm diameter at the distal end so the hybridcatheter can be attached to the walls in a manner that it can beconveniently introduced to the body. This enables four-way angulations(210° up, 90° down, and 100° right/left) a 140° field of view andclose-up high resolution image can be obtained as close as 2 mm from thetissue, so the laser blade catheter can be attached accordingly to thetip of the scope (relatively advanced in few mm at the front).

There is provided herein, in accordance with some embodiments, a hybridcatheter having a tip section having optical fibers for transmitting(pulse) laser radiation and inner and/or outer walls having facet thatare sharp enough to complete the cutting and debulking (extracting) ofleads initiated by the laser but not sharp enough to work alone in orderto maintain the procedure's safety. Using the hybrid catheter allowsdecreasing the requirements from the laser and thus enables use of smallsolid state lasers, in such way that when the debulking of the leads isnot completed by laser cutting the tissue surrounding the leads isperformed mechanically (by sharp wall(s) and/or by a blade).

Reference is now made to FIGS. 13A-C, which show cross sectionillustrations of three types of a hybrid catheter for pacemaker and ICD(Implantable Cardioverter Defibrillator) lead extraction.

FIG. 13A shows a cross section of hybrid catheter 2002 over lead 2000which is to be extracted. Catheter 2002 has a tip section 2004,typically having a circular cross section. Tip section 2004 comprises aninner wall 2006 and an outer wall 2008, at least one of which having asharp (for example tapered) distal end which thus function like blades.Optical fiber(s) 2010 are located between inner wall 2006 and outer wall2008 and are configured to transmit laser radiation through the distalend of tip section 2004 (as marked by the arrows). The laser radiationmodifies (e.g., ablate, partially ablate, weaken, cut, etc.) the tissuesurrounding the lead and thereby preparing the tissue for penetration ofthe sharp distal edge of inner wall 2006 and outer wall 2008, such thatwalls are configured to cut through the modified tissue and therebydetach lead 2000 from the tissue.

According to some embodiment, the catheter may include means to hold thelead in order to extract it from the body. These embodiment aim toreplace a complicated process known in the art wherein a lead lockingdevice is inserted (e.g. Spectranetics Lead Locking Device (LLD®)) andthen another catheter used for laser ablation (Spectranetics SLS® II) isinserted. Two examples of means for holding and retracting the lead areschematically illustrated in FIGS. 13B and 13C, in accordance with someembodiments.

FIG. 13B shows a cross section of hybrid catheter 3000 over lead 2000which is to be extracted. Catheter 3000 may be similar to catheter 2002,but further includes a “donut shaped” balloon (3002/3004) connected toan inner wall of hybrid catheter 3000. When hybrid catheter 3000 ispenetrating through the tissue surroundings lead 2000 the balloon isdeflated (3002). When hybrid catheter 3000 is pulled out in order toextract lead 2000 the balloon is inflated (3004) and “holds” lead 2000and thus assist in its extraction.

FIG. 13C shows a cross section of hybrid catheter 4000 over lead 2000which is to be extracted. Catheter 4000 may be similar to catheter 2002,but further includes “grabbing elements” 4002, configured to allowsmooth penetration of catheter 4000 through the tissue surroundings lead2000 but to hold lead 2000 in a predetermined force when moving outside.According to some embodiments, the catheter may include means to releasethis holding in cases there is a need to retract the catheter withoutthe lead.

In the description and claims of the application, each of the words“comprise” “include” and “have”, and forms thereof, are not necessarilylimited to members in a list with which the words may be associated. Inaddition, where there are inconsistencies between this application andany document referenced or incorporated by reference, it is herebyintended that the present application controls.

What is claimed is:
 1. A method for detaching and/or resecting anundesired tissue from an inner wall of a body cavity, the methodcomprising: introducing an atherectomy device into the body cavity,wherein said atherectomy device comprises at least one optical fibercoupled to a laser with high absorption in water; advancing theatherectomy device until reaching said undesired tissue; injecting anaqueous solution into the blood vessel; transmitting laser radiationtoward the undesired tissue, wherein the high absorption of laserradiation in said aqueous solution creates a water jet onto theundesired tissue, wherein the effect of the said water jet causesdetachment and/or resection of at least a part of the undesired tissue.2. The method of claim 1, wherein the atherectomy device comprises aninner tube creating a lumen, said inner tube being connected to a pumpand a tubular polymer formed around the inner tube; wherein said atleast one optical fiber is located between said inner tube and saidtubular polymer.
 3. The method of claim 2, further comprising aspiratingat least part of the undesired tissue through said inner tube using saidpump.
 4. The method according to claim 1, wherein said at least oneoptical fiber comprises a plurality of optical fibers.
 5. The methodaccording to claim 2, wherein said pump is a vacuum pump.
 6. The methodaccording to claim 2, wherein said pump is a peristaltic pump.
 7. Themethod according to claim 1, wherein a wavelength of said laserradiation is in the mid IR range.
 8. The method according to claim 7,wherein said laser radiation is pulsed laser radiation having awavelength in the range of 2.8-3 microns.
 9. The method of claim 1,wherein the aqueous solution is injected through a nozzle positioned atthe distal edge of the atherectomy device.
 10. The method of claim 1,wherein the aqueous solution is saline.